First time working with a CNC shop and confused why prices for similar-looking parts can differ 10× or more? CNC pricing isn't simple "material × weight" — it's driven by 5 key cost components.
Note: this article describes proportions and relative impact only. Actual quotes vary with market prices, batch size, and complexity — always rely on individual quotes.
The 5 cost drivers
- Material (20-40%): You pay for the billet, not the finished part. SUS316 typically costs ~50-80% more than SUS304; titanium can be 15-25× the cost of aluminum.
- Machine time (30-50%): The biggest variable. 5-axis machine time is 1.5-2.5× the rate of 3-axis. Tight tolerances, deep pockets, thin walls, complex surfaces all multiply time.
- Programming & setup (5-20%): Fixed cost. Small batches pay disproportionately. Combine orders to amortize.
- Tooling (5-15%): Negligible for aluminum. For titanium/Inconel, tool life can drop to 1/10 — and ceramic/CBN inserts cost 5-15× standard carbide.
- Surface treatment (10-30%): Often overlooked. Anodizing +5-10%, hard anodizing +15-25%, PVD coating +30-50%.
How to design cheaper parts
Avoid unnecessary tight tolerances, minimize machined faces, avoid thin walls under 1mm, batch orders, standardize designs across SKUs.
Reading a quote
A proper quote breaks out material, machining, and surface treatment separately. Lump-sum quotes hide markup. Compare 3 quotes — variance under 30% is normal; quotes 60%+ below market often indicate cut corners.
